Minimum and maximum depth of the Sea of Okhotsk. Give a description of the Sea of Okhotsk according to the plan. Bottom and coastline
The Sea of Okhotsk is one of the largest and deepest seas in Russia. Here are important sea routes connecting Vladivostok with the northern regions of the Far East and the Kuril Islands. Major ports on the coast of the mainland - Magadan and Okhotsk; on Sakhalin Island - Korsakov; on the Kuril Islands - Severo-Kurilsk.
The Sea of Okhotsk was discovered by Russian explorers I. Yu. Moskvitin and V. D. Poyarkov in the first half of the 17th century. From 1733, work began on the Second Kamchatka Expedition, whose members made up detailed maps almost all of its coasts.
The Sea of Okhotsk, also called the Lamsky or Kamchatka Sea, is a semi-enclosed sea in the northwestern part of the Pacific Ocean. It washes the shores of Russia and Japan (Hokkaido Island).
From the west, it is bounded by the mainland Asia from Cape Lazarev to the mouth of the Penzhina River; from the north - the Kamchatka Peninsula; islands from the east Kuril ridge and from the south by the islands of Hokkaido and Sakhalin.
The Sea of Okhotsk is connected to the Pacific Ocean through the Kuril Straits. There are more than 30 such straits and their overall width over 500 kilometers. It has communication with the Sea of Japan through the Nevelskoy and La Perouse straits.
Characteristics of the Sea of Okhotsk
The sea is named after the river Okhota, which flows into it. Square Sea of Okhotsk is 1603,000 square kilometers. Its average depth is 1780 meters, with a maximum depth of 3916 meters. From north to south, the sea stretches for 2445 kilometers, and from east to west for 1407 kilometers. The approximate volume of water enclosed in it is 1365 thousand cubic kilometers.
The coastline of the Sea of Okhotsk is slightly indented. Its length is 10460 kilometers. Its largest bays are: Shelikhov Bay, Sakhalin Bay, Udskaya Bay, Tauyskaya Bay and Academy Bay. The northern, northwestern and northeastern shores are high and rocky. At the confluence of large rivers (Amur, Uda, Okhota, Gizhiga, Penzhina), as well as in the west of Kamchatka, in the northern part of Sakhalin and Hokkaido, the coasts are predominantly low.
From October to May-June, the northern part of the sea is covered with ice. The southeastern part practically does not freeze. In winter, the water temperature near the sea surface ranges from -1.8 °C to 2.0 °C, in summer the temperature rises to 10-18 °C.
The salinity of the surface waters of the Sea of Okhotsk is 32.8-33.8 ppm, while the salinity of coastal waters usually does not exceed 30 ppm.
Climate of the Sea of Okhotsk
The Sea of Okhotsk is located in the monsoon climate zone of temperate latitudes. For most of the year, cold dry winds blow from the mainland, cooling the northern half of the sea. From October to April, negative air temperatures and a stable ice cover are observed here.
In the northeastern part of the sea average temperature in January - February it fluctuates from - 14 to - 20 ° C. In the northern and western regions, the temperature varies from - 20 to - 24 ° C. In the southern and eastern parts of the sea, it is much warmer in winter from - 5 to - 7 ° C.
Average temperatures in July and August, respectively, wound 10-12 ° C; 11-14°C; 11-18 ° C. Annual rainfall in different places Sea of Okhotsk is also different. So in the north, 300-500 mm of precipitation falls annually; in the west up to 600-800 mm; in the southern and southeastern parts of the sea - over 1000 mm.
According to the composition of organisms living in the Sea of Okhotsk, it is more of an arctic character. Due to the thermal effect of oceanic waters, species of the temperate zone are predominantly inhabited by the southern and southeastern parts of the sea.
Numerous settlements of mussels, littorinas and other mollusks, barnacles, sea urchins, and many crabs are noted in coastal zones.
A rich fauna of invertebrates has been discovered at great depths of the Sea of Okhotsk. Glass sponges, holothurians, deep-sea corals, decapods live here.
The Sea of Okhotsk is rich in fish. The most valuable are salmon species: chum salmon, pink salmon, coho salmon, chinook salmon and sockeye salmon. There is an industrial catch of herring, pollock, flounder, cod, navaga, capelin and smelt.
Large mammals live in the Sea of Okhotsk - whales, seals, sea lions and fur seals. There are many sea birds that arrange noisy "bazaars" on the coasts.
The UN recognized the enclave of the Sea of Okhotsk as part of the Russian shelf
Inessa Dotsenko
The UN Commission on the Limits of the Continental Shelf recognized the enclave of the Sea of Okhotsk with an area of 52,000 square kilometers as part of the Russian continental shelf.
According to ITAR-TASS, this was stated by Russian Minister of Natural Resources and Ecology Sergei Donskoy.
We have officially received a document from the UN Commission on the Continental Shelf on the satisfaction of our application to recognize the enclave in the Sea of Okhotsk as the Russian shelf. This is an event that has actually taken place, so I would like to congratulate everyone on this,” he said.
The commission's decision, according to the minister, is unconditional and has no retroactive effect. Now the enclave is fully subject to Russian jurisdiction.
According to ITAR-TASS, Donskoy also said that Russia's application for the expansion of the continental shelf in the Arctic will be ready this fall.
All the resources that will be found there - everything will be mined exclusively within the framework of Russian legislation, - said Donskoy. He said that, according to geologists, the total volume of hydrocarbons discovered in this area exceeds one billion tons.
Magadan Governor Vladimir Pecheny believes that the recognition of the enclave in the middle of the Sea of Okhotsk as part of the Russian continental shelf opens up new prospects for the economy of Kolyma and the entire Far East. First of all, it will relieve the fishermen of the region from numerous administrative barriers.
Firstly, fishing for fish, crabs, shellfish can be carried out freely anywhere in the Sea of Okhotsk. Special permits from the border service will not be required both when going to sea and upon returning. Second, when Russian territory there will be not only a 200-mile zone, but the whole sea, we will get rid of the poaching of foreign fishermen in our waters. It will be easier to keep the unique environment, - the press service of the government of the region quotes the words of Baked.
Reference
In the center of the Sea of Okhotsk there is an elongated enclave of considerable size. Previously, all of it was considered "open sea". Vessels of any state could freely move and fish on its territory. In November 2013, Russia managed to prove the rights to 52,000 square kilometers of water in the center of the Sea of Okhotsk. For comparison, this is more than the area of Holland, Switzerland or Belgium. The center of the Sea of Okhotsk ceased to be part of the World Ocean and became completely Russian. After approval at the UN session, the process of legally assigning the enclave to the Russian continental shelf can be considered fully completed.
The Sea of Okhotsk juts out rather deeply into the land and is noticeably elongated from the southwest to the northeast. It has coastlines almost everywhere. It is separated from the Sea of Japan by about. Sakhalin and conditional lines of Cape Suschev - Cape Tyk (Nevelskoy Strait), and in the La Perouse Strait - Cape Soya - Cape Crillon. The southeastern boundary of the sea runs from Cape Nosappu (Hokkaido Island) and through the Kuril Islands to Cape Lopatka (Kamchatka Peninsula).
The Sea of Okhotsk is one of the largest and deep seas peace. Its area is 1,603 thousand km 2, volume - 1,316 thousand km 3, average depth- 821 m, maximum depth - 3,521 m.
The Sea of Okhotsk belongs to the marginal seas of the mixed continental-oceanic type. It is separated from the Pacific Ocean by the Kuril ridge, which has about 30 large, many small islands and rocks. The Kuril Islands are located in the seismic activity belt, which includes more than 30 active and 70 extinct volcanoes. Seismic activity is manifested on the islands and under water. In the latter case, tsunami waves often form. In the sea there is a group of the Shantar Islands, the Spafaryev, Zavyalov, Yamsky and small island Iona is the only one of all remote from the coast. With a large length coastline relatively weakly cut. At the same time, it forms several large bays (Aniva, Patience, Sakhalin, Academies, Tugursky, Ayan, Shelikhov) and bays (Udskaya, Tauiskaya, Gizhiginskaya and Penzhinskaya).
The Nevelskoy and La Perouse straits are comparatively narrow and shallow. The width of the Nevelskoy Strait (between Capes Lazarev and Pogibi) is only about 7 km. The width of the La Perouse Strait is 43-186 km, the depth is 53-118 m.
The total width of the Kuril Straits is about 500 km, and maximum depth the deepest of them, the Bussol Strait, exceeds 2300 m. Thus, the possibility of water exchange between the Sea of Japan and the Sea of Okhotsk is incomparably less than between the Sea of Okhotsk and the Pacific Ocean.
However, even the depth of the deepest of the Kuril straits is much less than the maximum depth of the sea, and therefore the Kuril ridge is a huge threshold that separates the sea basin from the ocean.
The most important for water exchange with the ocean are the straits of Bussol and Krusenstern, since they have largest area and depth. The depth of the Bussol Strait was indicated above, and the depth of the Kruzenshtern Strait is 1920 m. The Frieze, Fourth Kuril, Rikord and Nadezhda straits are of less importance, the depths of which are more than 500 m. The depths of the remaining straits generally do not exceed 200 m, and their areas are insignificant.
On distant shores
The shores of the Sea of Okhotsk different areas belong to different geomorphological types. For the most part these are abrasion shores altered by the sea, and only in Kamchatka and Sakhalin are accumulative shores found. In general, the sea is surrounded by high and steep shores. In the north and northwest, rocky ledges descend directly to the sea. The coasts along the Sakhalin Bay are low. The southeastern coast of Sakhalin is low, and the northeastern coast is low. The shores of the Kuril Islands are very steep. The northeastern coast of Hokkaido is predominantly low-lying. The coast of the southern part of Western Kamchatka has the same character, but the coast of its northern part rises somewhat.
Shores of the Sea of Okhotsk
Bottom relief
The bottom relief of the Sea of Okhotsk is varied. Northern part The sea is a continental shelf - an underwater continuation of the Asian mainland. The width of the continental shoal in the area of the Ayano-Okhotsk coast is approximately 185 km, in the area of the Uda Bay - 260 km. Between the meridians of Okhotsk and Magadan, the width of the shoal increases to 370 km. From the western edge of the sea basin there is an island sandbar of Sakhalin, from the east - a sandbank of Kamchatka. The shelf occupies about 22% of the bottom area. The rest, most (about 70%) of the sea is located within the continental slope (from 200 to 1500 m), on which separate underwater heights, depressions and trenches stand out.
The deepest, southern part of the sea (more than 2500 m), which is a part of the bed, occupies 8% of the total area of the sea. It is stretched as a strip along the Kuril Islands and gradually narrows from 200 km against about. Iturup up to 80 km against the Krusenstern Strait. Great depths and significant bottom slopes distinguish southwestern part sea from the northeast, lying on the continental shelf.
Of the major elements of the relief of the bottom of the central part of the sea, two underwater hills stand out - the Academy of Sciences and the Institute of Oceanology. Together with the protrusion of the continental slope, they divide the sea basin into three basins: the northeastern one - the TINRO basin, the northwestern one - the Deryugin basin, and the southern deep-water basin - the Kuril basin. The depressions are connected by gutters: Makarov, P. Schmidt and Lebed. To the northeast of the TINRO depression, the Shelikhov Bay trough extends.
The least deep is the TINRO basin, located to the west of Kamchatka. Its bottom is a plain lying at a depth of about 850 m, with a maximum depth of 990 m.
The Deryugin depression is located to the east of the Sakhalin submerged base. Its bottom is a flat, elevated plain at the edges, lying on average at a depth of 1700 m, the maximum depth of the depression is 1744 m.
The deepest Kuril depression. This is a huge flat plain lying at a depth of about 3300 m. Its width in the western part is about 212 km, and its length in the northeast direction is about 870 km.
Bottom relief and currents of the Sea of Okhotsk
currents
Under the influence of winds and water inflow through the Kuril Straits, character traits systems of non-periodic currents of the Sea of Okhotsk. The main one is the cyclonic system of currents, covering almost the entire sea. It is due to the predominance of cyclonic circulation of the atmosphere over the sea and the adjacent part of the Pacific Ocean. In addition, stable anticyclonic gyres are traced in the sea: to the west of the southern tip of Kamchatka (approximately between 50-52°N and 155-156°E); above the TINRO depression (55-57°N and 150-154°E); in the area of the Southern Basin (45-47°N and 144-148°E). In addition, a vast area of cyclonic circulation of waters is observed in the central part of the sea (47-53 ° N and 144-154 ° E), and a cyclonic circulation is observed to the east and north-east of the northern tip of the island. Sakhalin (54-56°N and 143-149°E).
Strong currents bypass the sea along the coastline counterclockwise: the warm Kamchatka Current, directed northward into Shelikhov Bay; flow of western and then south-western direction along the northern and northwestern coasts of the sea; the steady East Sakhalin Current going south, and the rather strong Soya Current entering the Sea of Okhotsk through the Laperouse Strait.
On the southeastern periphery of the cyclonic gyre in the central part of the sea, a branch of the Northeast Current is distinguished, which is opposite in direction to the Kuril Current in the Pacific Ocean. As a result of the existence of these streams, stable areas of convergence of currents are formed in some of the Kuril Straits, which leads to subsidence of waters and has a significant effect on the distribution of oceanological characteristics not only in the straits, but also in the sea itself. And finally, one more feature of the water circulation in the Sea of Okhotsk is two-way stable currents in most of the Kuril straits.
Surface currents on the surface of the Sea of Okhotsk are most intense near the western coast of Kamchatka (11–20 cm/s), in the Sakhalin Bay (30–45 cm/s), in the area of the Kuril Straits (15–40 cm/s), over the South Basin ( 11-20 cm/s) and during the Soya (up to 50-90 cm/s). In the central part of the cyclonic region, the intensity of horizontal transport is much less than on its periphery. In the central part of the sea, velocities vary from 2 to 10 cm/s, with velocities below 5 cm/s predominating. A similar picture is observed in Shelikhov Bay: rather strong currents near the coast (up to 20–30 cm/s) and low velocities in the central part of the cyclonic gyre.
In the Sea of Okhotsk are well expressed different kinds periodic tidal currents: semidiurnal, diurnal and mixed with a predominance of semidiurnal or diurnal components. The velocities of tidal currents range from a few centimeters to 4 m/s. Away from the coast, the current velocities are small - 5-10 cm/s. In straits, bays and off the coast, their speeds increase significantly. For example, in the Kuril Straits, current velocities reach 2-4 m/s.
The tides of the Sea of Okhotsk have a very complex character. A tidal wave enters from the south and southeast from the Pacific Ocean. The semidiurnal wave moves to the north, and at the 50° parallel it is divided into two parts: the western one turns to the northwest, the eastern one moves towards Shelikhov Bay. The diurnal wave also moves to the north, but at the latitude of the northern tip of Sakhalin it is divided into two parts: one enters Shelikhov Bay, the other reaches the northwestern coast.
Diurnal tides are the most widespread in the Sea of Okhotsk. They are developed in the Amur Estuary, Sakhalin Bay, on the coast of the Kuril Islands, off the western coast of Kamchatka and in Penzhinsky Bay. Mixed tides are observed on the northern and northwestern coasts of the sea and in the area of the Shantar Islands.
The highest tides (up to 13 m) were recorded in the Penzhina Bay (cape Astronomichesky). In the area of the Shantar Islands, the tide exceeds 7 m. The tides are significant in the Sakhalin Bay and in the Kuril Straits. In the northern part of the sea, their size reaches 5 m.
Fur seal rookery
The lowest tides were observed off the eastern coast of Sakhalin, in the area of the La Perouse Strait. In the southern part of the sea, the tides are 0.8-2.5 m.
In general, tidal level fluctuations in the Sea of Okhotsk are very significant and have a significant impact on its hydrological regime, especially in coastal zone.
In addition to tidal fluctuations, surge fluctuations in the level are also well developed here. They occur mainly during the passage of deep cyclones over the sea. Surge rises in the level reach 1.5-2 m. The largest surges are noted on the coast of Kamchatka and in the Gulf of Patience.
Significant size and great depths Sea of Okhotsk, frequent and strong winds over it cause the development of large waves here. The sea is especially stormy in autumn, and in ice-free areas in winter. These seasons account for 55-70% of storm waves, including those with wave heights of 4-6 m, and greatest heights waves reach 10-11 m. The most restless are the southern and southeastern regions of the sea, where the average frequency of storm waves is 35-40%, and in the northwestern part it decreases to 25-30%. With strong excitement in the straits between the Shantar Islands, a crowd is formed.
Climate
The Sea of Okhotsk is located in the monsoon climate zone of temperate latitudes. A significant part of the sea in the west deeply protrudes into the mainland and lies relatively close to the cold pole of the Asian land, so the main source of cold for the Sea of Okhotsk is located to the west of it. Relatively high ridges Kamchatka impedes the penetration of warm Pacific air. Only in the southeast and south is the sea open to the Pacific Ocean and Sea of Japan where it receives a significant amount of heat. However, the influence of cooling factors is stronger than warming factors, so the Sea of Okhotsk is generally cold. At the same time, due to the large meridional extent, there are significant differences in the synoptic situation and meteorological conditions. In the cold part of the year (from October to April), the Siberian anticyclone and the Aleutian low act on the sea. The influence of the latter extends mainly to the southeastern part of the sea. This distribution of large-scale baric systems causes strong persistent northwestern and northern winds often reaching storm strength. Low winds and calms are almost completely absent, especially in January and February. In winter, the wind speed is usually 10-11 m/s.
The dry and cold Asian winter monsoon significantly cools the air over the northern and northwestern regions of the sea. In the coldest month - January - the average air temperature in the north-west of the sea is -20 - 25 °, in central regions–10-15°, and in the south-eastern part of the sea it is equal to –5-6°.
In autumn and winter, cyclones of predominantly continental origin come out to sea. They bring with them an increase in wind, sometimes a decrease in air temperature, but the weather remains clear and dry, as continental air comes from the cooled mainland. In March-April, large-scale baric fields are restructured. The Siberian anticyclone is collapsing, and the Hawaiian high is intensifying. As a result, during the warm season (from May to October), the Sea of Okhotsk is under the influence of the Hawaiian maximum and the area of low pressure located over Eastern Siberia. At this time, weak southeasterly winds prevail over the sea. Their speed usually does not exceed 6-7 m/s. Most often, these winds are observed in June and July, although stronger northwesterly and northerly winds are sometimes observed in these months. In general, the Pacific (summer) monsoon is weaker than the Asian (winter) monsoon, since the horizontal pressure gradients are smoothed out in the warm season.
In summer, the average monthly air temperature in August decreases from the southwest (from 18°) to the northeast (up to 10-10.5°).
During the warm season over southern part seas quite often pass tropical cyclones - typhoons. They are associated with an increase in wind to a storm, which can last up to 5-8 days. The predominance of southeasterly winds in the spring-summer season leads to significant cloudiness, precipitation, and fog.
Monsoon winds and stronger winter cooling of the western part of the Sea of Okhotsk compared to the eastern part are important climatic features this sea.
Quite a few mostly small rivers flow into the Sea of Okhotsk, therefore, with a significant volume of its waters, the continental runoff is relatively small. It is equal to about 600 km 3 /year, while about 65% of the flow comes from the Amur. Others comparatively major rivers- Penzhina, Okhota, Uda, Bolshaya (in Kamchatka) - bring much less to the sea fresh water. The flow comes mainly in spring and early summer. At this time, its greatest influence is felt mainly in the coastal zone, near the mouth areas of large rivers.
Hydrology and water circulation
Geographical position, large extent along the meridian, monsoonal change of winds and good connection seas with the Pacific Ocean through the Kuril Straits - the main natural factors, which most significantly affect the formation of the hydrological conditions of the Sea of Okhotsk. The values of heat input and output in the sea are determined mainly by the rational heating and cooling of the sea. The heat brought by the Pacific waters is of subordinate importance. However, for the water balance of the sea, the inflow and outflow of water through the Kuril Straits plays a decisive role.
The flow of surface Pacific waters into the Sea of Okhotsk occurs mainly through the northern straits, in particular through the First Kuril. In the straits of the middle part of the ridge, both the inflow of Pacific waters and the outflow of Okhotsk waters are observed. So, in the surface layers of the Third and Fourth straits, apparently, there is a runoff of water from the Sea of Okhotsk, in the near-bottom ones - an inflow, and in the Bussol Strait - on the contrary: in the surface layers - an inflow, in the deep - a drain. In the southern part of the ridge, mainly through the straits of Ekaterina and Friza, there is mainly a runoff of water from the Sea of Okhotsk. The intensity of water exchange through the straits can vary significantly.
In the upper layers of the southern part of the Kuril ridge, the runoff of the Sea of Okhotsk waters predominates, and in the upper layers of the northern part of the ridge, Pacific waters enter. In the deep layers, the inflow of Pacific waters prevails.
Water temperature and salinity
The inflow of Pacific waters significantly affects the distribution of temperature, salinity, formation of the structure and general circulation of the waters of the Sea of Okhotsk. It is characterized by a subarctic structure of waters, in which cold and warm intermediate layers are well expressed in summer. A more detailed study of the subarctic structure in this sea has shown that the Sea of Okhotsk, Pacific, and Kuril varieties of the subarctic water structure exist in it. With the same nature of the vertical structure, they have quantitative differences in the characteristics of water masses.
The following water masses are distinguished in the Sea of Okhotsk:
surface water mass with spring, summer and autumn modifications. It is a thin heated layer 15-30 m thick, which limits the upper maximum of stability, mainly due to temperature. This water mass is characterized by temperature and salinity corresponding to each season;
The Sea of Okhotsk water mass is formed in winter from surface water and in spring, summer and autumn it manifests itself in the form of a cold intermediate layer lying between horizons of 40-150 m. This water mass is characterized by a fairly uniform salinity (31-32.9‰) and different temperatures. In most of the sea, its temperature is below 0 ° and reaches -1.7 °, and in the region of the Kuril Straits it is above 1 °;
the intermediate water mass is formed mainly due to the sinking of waters along the underwater slopes, located within the sea from 100-150 to 400-700 m, and is characterized by a temperature of 1.5 ° and a salinity of 33.7‰. This water mass is distributed almost everywhere, except for the northern part of the sea, Shelikhov Bay and some areas along the coast of Sakhalin, where the Sea of Okhotsk water mass reaches the bottom. The thickness of the intermediate water mass layer decreases from south to north;
the deep Pacific water mass is the water of the lower part of the warm layer of the Pacific Ocean, which enters the Sea of Okhotsk at horizons below 800-1000 m, i.e. below the depth of the waters descending in the straits, and in the sea it appears as a warm intermediate layer. This water mass is located on the horizons of 600-1350 m, has a temperature of 2.3°C and a salinity of 34.3‰. However, its characteristics change in space. The highest values of temperature and salinity are observed in the northeastern and partly in northwestern regions, which is associated here with the rise of waters, and the smallest values of characteristics are characteristic of western and southern regions where the water falls.
The water mass of the southern basin is of Pacific origin and represents the deep water of the northwestern part of the Pacific Ocean near the horizon of 2300 m, i.e. horizon corresponding to the maximum depth of the threshold in the Kuril Straits, located in the Bussol Strait. This water mass fills the basin from a horizon of 1350 m to the bottom and is characterized by a temperature of 1.85° and a salinity of 34.7‰, which vary only slightly with depth.
Among the identified water masses, the Sea of Okhotsk and the deep Pacific Ocean are the main ones; they differ from each other not only in thermohaline, but also in hydrochemical and biological indicators.
The water temperature on the sea surface decreases from south to north. In winter, almost everywhere, the surface layers cool down to a freezing temperature of -1.5-1.8°. Only in the southeastern part of the sea does it remain around 0°, and near the northern Kuril Straits, under the influence of Pacific waters, the water temperature reaches 1-2°.
Spring warming at the beginning of the season mainly goes to the melting of ice, only towards the end of it does the water temperature begin to rise.
In summer, the distribution of water temperature on the sea surface is quite diverse. In August, the waters adjacent to about. Hokkaido. In the central regions of the sea, the water temperature is 11-12°. The coldest surface waters are observed near about. Iona, near Cape Pyagin and near the Kruzenshtern Strait. In these areas, the water temperature is kept within 6-7 °. The formation of local centers of increased and decreased water temperature on the surface is mainly associated with the redistribution of heat by currents.
The vertical distribution of water temperature varies from season to season and from place to place. In the cold season, the change in temperature with depth is less complex and varied than in warm seasons.
In winter, in the northern and central regions of the sea, water cooling extends to horizons of 500–600 m. The water temperature is relatively uniform and varies from -1.5–1.7 ° on the surface to rises to 1-0°, in the southern part of the sea and near the Kuril Straits, the water temperature drops from 2.5-3° on the surface to 1-1.4° at the horizons of 300-400 m and then gradually rises to 1.9-2 ,4° in the bottom layer.
In summer, surface waters are warmed up to a temperature of 10-12°C. In the subsurface layers, the water temperature is slightly lower than on the surface. A sharp decrease in temperature to -1 - 1.2 ° is observed between horizons of 50-75 m, deeper, up to horizons of 150-200 m, the temperature quickly rises to 0.5 - 1 °, and then it rises more smoothly, and at horizons of 200 - 250 m is equal to 1.5 - 2 °. Further, the temperature of the water almost does not change to the bottom. In the south and southeastern parts sea, along the Kuril Islands, the water temperature drops from 10 - 14 ° on the surface to 3 - 8 ° at a horizon of 25 m, then to 1.6-2.4 ° at a horizon of 100 m and to 1.4-2 ° at the bottom . The vertical temperature distribution in summer is characterized by a cold intermediate layer. In the northern and central regions of the sea, the temperature in it is negative, and only near the Kuril Straits does it have positive values. In different areas of the sea, the depth of the cold intermediate layer is different and varies from year to year.
The distribution of salinity in the Sea of Okhotsk varies relatively little from season to season. Salinity increases in the eastern part, which is under the influence of Pacific waters, and decreases in the western part, which is desalinated by continental runoff. In the western part, salinity on the surface is 28-31‰, and in the eastern part - 31-32‰ and more (up to 33‰ near the Kuril ridge),
In the northwestern part of the sea, due to desalination, the salinity on the surface is 25‰ or less, and the thickness of the desalinated layer is about 30-40 m.
Salinity increases with depth in the Sea of Okhotsk. At the horizons of 300-400 m in the western part of the sea, the salinity is 33.5‰, and in the eastern part it is about 33.8‰. At a horizon of 100 m, salinity is 34‰ and further towards the bottom it increases slightly, by only 0.5-0.6‰.
In individual bays and straits, salinity and its stratification may differ significantly from the waters of the open sea, depending on local conditions.
In accordance with temperature and salinity, denser waters are observed in winter in the northern and central regions of the sea covered with ice. Some less density in a relatively warm Kuril region. In summer, the water density decreases, its lowest values are confined to the zones of influence of coastal runoff, and the highest values are observed in the areas of distribution of Pacific waters. In winter, it rises slightly from the surface to the bottom. In summer, its distribution depends on temperature in the upper layers, and on salinity in the middle and lower horizons. In summer, a noticeable density stratification of waters along the vertical is created, the density increases especially noticeably at horizons of 25-50 m, which is associated with the heating of waters in open areas and desalination near the coast.
Wind mixing is carried out in the ice-free season. It flows most intensively in spring and autumn, when strong winds blow over the sea, and the stratification of waters is not yet very pronounced. At this time, wind mixing extends to horizons of 20-25 m from the surface.
Intense ice formation over most of the sea excites an enhanced thermohaline winter vertical circulation. At depths up to 250-300 m, it spreads to the bottom, and below it is prevented by the maximum stability that exists here. In areas with a rugged bottom topography, the spread of density mixing into the lower horizons is facilitated by the sliding of water along the slopes.
ice coverage
Severe and long winters with strong northwest winds contribute to the development of large masses of ice in the sea. The ice of the Sea of Okhotsk is exclusively of local formation. Here there are both fixed ice - fast ice, and floating ice, representing the main form of sea ice.
In different amounts, ice is found in all areas of the sea, but in summer the entire sea is cleared of ice. The exception is the region of the Shantar Islands, where ice can persist in summer.
Ice formation begins in November in the bays and bays of the northern part of the sea, in the coastal part of the island. Sakhalin and Kamchatka. Then ice appears in the open part of the sea. In January and February, ice covers the entire northern and middle parts of the sea.
In ordinary years, the southern boundary of a relatively stable ice cover bends to the north and runs from the La Perouse Strait to Cape Lopatka.
The extreme southern part of the sea never freezes. However, due to the winds, significant masses of ice are carried into it from the north, often accumulating near the Kuril Islands.
From April to June there is a destruction and gradual disappearance of the ice cover. On average, the ice in the sea disappears in late May - early June. The northwestern part of the sea, due to the currents and the configuration of the coasts, is most of all clogged with ice, which persists until July. The ice cover in the Sea of Okhotsk lasts for 6-7 months. More than 3/4 of the sea surface is covered with floating ice. Close-knit ice in the northern part of the sea presents serious obstacles to navigation even for icebreakers.
The total duration of the ice period in the northern part of the sea reaches 280 days a year.
The southern coast of Kamchatka and the Kuril Islands are areas with low ice coverage: here, on average, ice stays for no more than three months a year. The thickness of the ice growing during the winter reaches 0.8-1 m.
strong storms, tidal currents they break open the ice cover in many areas of the sea, forming hummocks and large leads. In the open part of the sea, solid immovable ice is never observed, usually drifting ice here, in the form of vast fields with numerous leads.
Part of the ice from the Sea of Okhotsk is carried into the ocean, where it breaks up and melts almost immediately. In severe winters, floating ice is pressed against the Kuril Islands by northwestern winds and clogs some of the straits.
Economic importance
There are about 300 species of fish in the Sea of Okhotsk. Of these, about 40 species are commercial. The main commercial fish are pollock, herring, cod, navaga, flounder, sea bass, capelin. Catches of salmon (chum salmon, pink salmon, sockeye salmon, coho salmon, chinook salmon) are small.
Map of the Sea of Okhotsk - water temperature of the Sea of Okhotsk
The water temperature on the sea surface decreases from south to north. In winter, almost everywhere, the surface layers cool down to a freezing temperature of –1.5...–1.8°C. Only in the southeastern part of the sea does it stay around 0°C, and near the northern Kuril Straits, under the influence of Pacific waters, the water temperature reaches 1–2°C.
Spring warming at the beginning of the season mainly goes to the melting of ice, only towards the end of it does the water temperature begin to rise.
In summer, the distribution of water temperature on the sea surface is quite diverse. In August, the waters adjacent to the island of Hokkaido are warmest (up to 18–19°C). In the central regions of the sea, the water temperature is 11–12°С. The coldest surface waters are observed near Iona Island, near Cape Pyagin and near the Kruzenshtern Strait. In these areas, the water temperature is kept in the range of 6-7°C. The formation of local centers of increased and decreased water temperature on the surface is mainly associated with the redistribution of heat by currents.
The vertical distribution of water temperature varies from season to season and from place to place. In the cold season, the change in temperature with depth is less complex and varied than in warm seasons.
In winter, in the northern and central regions of the sea, water cooling extends to horizons of 500–600 m. The water temperature is relatively uniform and varies from –1.5 ... 600 m, deeper it rises to 1–0°С, in the southern part of the sea and near the Kuril Straits, the water temperature drops from 2.5–3°С on the surface to 1–1.4°С at horizons of 300–400 m and further gradually rises to 1.9–2.4°C in the bottom layer.
In summer, surface waters are warmed up to a temperature of 10–12°С. In the subsurface layers, the water temperature is slightly lower than on the surface. A sharp decrease in temperature to –1...–1.2°С is observed between horizons of 50–75 m, deeper, to horizons of 150–200 m, the temperature quickly rises to 0.5–1°С, and then it rises more smoothly , and at the horizons of 200–250 m it is 1.5–2°С. Further, the temperature of the water almost does not change to the bottom. In the southern and southeastern parts of the sea, along the Kuril Islands, the water temperature drops from 10–14°С at the surface to 3–8°С at the 25 m horizon, then to 1.6–2.4°С at the 100 m horizon. and up to 1.4–2°C near the bottom. The vertical temperature distribution in summer is characterized by a cold intermediate layer. In northern and central regions
sea temperature in it is negative, and only near the Kuril Straits does it have positive values. In different areas of the sea, the depth of the cold intermediate layer is different and varies from year to year.
The depth of the Sea of Okhotsk reaches an average of 1780 m, and the maximum is approximately 3916 m. At the same time, its area is 1603 thousand km². It does not have the same depth, in the west it is less than in the eastern part. Many scientists classify it as semi-closed. It washes the Asian part of Eurasia and belongs to the Pacific Ocean.
Map of the Sea of Okhotsk
The Sea of Okhotsk washes the shores of the two states of Japan and. It is called Hokkai, literally - Northern. However, due to the existence of such a sea in atlantic ocean distribution received a new name, derived from the word Okhotsk - Okhotsuku-ka.
It is noteworthy that most of the territory of this sea belongs to the internal waters of these states and only a small part of it, according to the norms of international maritime law, is the open sea.
With the Pacific Ocean, this sea is connected by a number of straits located between the Kuril Islands. There are also exits to. They are connected by two straits through the Amur estuary: Tatar and Nevelskoy. And also through the La Perouse Strait. From the north and west, this sea is limited by the continental coast. In the east - the Kamchatka Peninsula and the islands. In the South - the island of Hokaido and the island of Sakhalin.
Speaking about the coastline, it should be noted that it is not very homogeneous. So in the north, the coast is noticeably more indented than in the western part. The largest bay of this sea is located in the northeast of the Sea of Okhotsk and is called Shelikhov Bay. Moreover, quite large bays in this sea are: Eyrineyskaya Bay, Babushkina, Zabiyaka, Sheltinga and Kekurny bays. East End The sea, washing the Kamchatka Peninsula, has practically no bays.
Surface water temperatures reach an average of 1.8°C in winter and range from 10 to 18°C in summer. It should be noted that in winter period, or rather, somewhere from October to May, sometimes until mid-June, the part of the sea located in the north is covered with ice. While the southern one usually does not freeze. Surface layer sea water has approximately - 33.8% salinity.
This sea is characterized by mixed and diurnal tides. Their maximum amplitude is recorded in the area of the Gizhiginskaya Bay, where it sometimes reaches 13 m.
Okhotsk fauna and flora
If we consider living creatures living in this sea, one can easily notice the heterogeneity of their composition in the northern and southern parts. In the north, it is inhabited for the most part by species characteristic of the Arctic seas, while in the south by those that usually live in a temperate maritime climate.
A large amount of plankton, especially zooplankton, is food for fish living in these waters. Diatoms are the most numerous among phytoplankton. Enough here and red, brown, and green algae. In addition, here you can find vast meadows of Zostera - sea grass. In general, there are more than 300 species of them in the Sea of Okhotsk.
There are also many species of fish here, in the northern part there are 123 species, and in the southern part there are more than 300. Among them, there are many deep-sea ones. In terms of fishing, halibut, cod, chum salmon, ivasi, pollock, pink salmon, flounder, coho salmon and even chinook salmon are most often caught. Salmon fishing is limited. This is due to a significant decrease in their population due to overfishing in the past. On this moment an artificial increase in their number.
There are also crustaceans here, moreover, crabbing is carried out at west coast. Takes here and marine mammals, among which fishing is carried out for seals, beluga whales and seals.
The Sea of Okhotsk has an important transport value, in addition, it is of interest for oil production. IN historical plan it is not easy to single out significant events in it. Quite important naval battles took place here during the Russo-Japanese War.
Traveling on Okhotsk - for extreme people
How tourist area this sea is not used due to the cold climate. But the pristine nature will attract the attention of fans of extreme sports. Lots of rare plants natural landscape, the opportunity to watch seals resting on rocks or unique birds nesting here. A multitude of diverse species, both marine and land-dwelling animals, and the incomparable view of the steel-gray sky and the sea surface leave an indelible impression.
And many feet under the keel!)))
The Sea of Okhotsk is one of the most large reservoirs on the entire planet. It is also one of the richest in terms of biological resources. The sea provides about 60% of the entire Russian Federation. Rare and endangered species live in its waters, and there are noisy "bird markets" on the banks.
The western border of the Sea of Okhotsk is drawn along the eastern coast of two islands: Sakhalin and Hokkaido. According to its physical and geographical characteristics, it is an inland sea. The Sea of Okhotsk also belongs to the seas of the so-called mixed continental-marginal type. Its area is 1603 thousand square meters. km. And the average depth is 821 m. The maximum depth of the Sea of Okhotsk is 3916 m.
Straits of the Sea of Okhotsk
The Amur estuary, and also - these are the channels through which the Sea of \u200b\u200bOkhotsk connects with the Sea of \u200b\u200bJapan. Which ocean gives rise to the Sea of Japan? It, like the Okhotsk, belongs to the waters of the Pacific Ocean. With the help of a huge number of Kuril straits, the sea is also connected to the Pacific Ocean. The deepest are the straits of the Bussol and Krusenstern islands. According to the classification of geographer N. Zubov, the Sea of Okhotsk belongs to the category of basin seas. The depth of its straits is much less than the depth of the basin.
Islands of the Sea of Okhotsk
The part of which ocean the Sea of Okhotsk is, also determines its shape. This part of the Pacific Ocean is a large number of islands of various origins. But the coastline itself is considered relatively flat. The islands of the sea differ in their shape. There are also those that are located in the waters in compactly compressed groups. There are also singles. The map of the Sea of Okhotsk is dotted with many islands, including those that are in the zone of seismic activity (for example, these are the Kuriles). Scientists also distinguish the so-called islands of the transition zone. The first group includes those that are formed by a single lithospheric plate with the mainland.
And the second geographers include those that have the shape of elongated archipelagos. The first group includes small islands located near East Sakhalin. These are Seals and the Stone of Danger. Seal Island has a flat surface and steep banks. And the Danger Stone, in fact, is a group of bare stones located in the La Perouse Strait. Two hundred kilometers. from about. Sakhalin is located on Iona with rocky shores. Its height is about 150 m. And in the northwest is the Shantar archipelago, which includes about 15 islands, the territory of which is 2.5 km 2. IN Southern Kuriles included the islands of the so-called Great Kuril Ridge.
Salinity and temperature
The salinity of the waters is determined by the part of which ocean the Sea of Okhotsk is. The salinity of the sea is in many ways similar to the data of the Pacific Ocean. surface water Sea of Okhotsk have a salinity of 32.8-33.8 ppm. The intermediate layer has a salinity of 34.5 ppm. It is known that in the Pacific Ocean this figure is on average 30-35 ppm. The temperature at the surface of the water in the sea during the cold season ranges from -1.8°С to +2°С. In summer, the figures rise to + 18 ° С. But at a depth of about 50-150 meters, the water temperature remains constant year-round. It is about -1.7°C. Warmer waters with a temperature of about 2-3°C enter the sea through the Kuril Straits.
Sea ownership
Since March 2003, Russia has been recognized as the official right to the enclave of the sea. The Sea of Okhotsk, or rather, a significant part of its shelf with an area of \u200b\u200babout 52 thousand square meters. km. is now in the possession of the Russian Federation. This event was especially important for local fishermen. After all, before they could not fish anywhere in the sea. After the transfer of the Sea of Okhotsk to Russia, they will no longer have competitors from other countries who previously had to give away part of the fish they caught. In addition, other workers in the industrial industry since then have been able to cross the sea area along the most convenient route.
Biodiversity
"The Sea of Okhotsk - the basin of which ocean?" - this question is also often asked in connection with the description of its marine wealth. Animal world The sea is rich in species that came to these waters from the Pacific territories. Crabs, shrimps, sea urchins and stars, seals, whales, fur seals live here. According to some estimates, it ranks first in the world in terms of the number of crabs. It is in the waters of the Sea of \u200b\u200bOkhotsk that the giant king crab lives, the leg span of which can reach 1.5 m.
About 200 species of fish are also found in the sea - these are herring, cod, navaga, pollock, capelin. Also in this area you can often meet sharks. Their species composition is similar Bering Sea: katran, polar and salmon sharks are found here.
Other riches
The Sea of Okhotsk is rich not only in fish stocks, crabs and various shellfish. Geologists say that about 40% of the territory of its shelf are sources of black gold - oil. There are also rich deposits of natural gas. Many experts tend to believe that the amount of oil deposits at the bottom of the sea exceeds three billion barrels. But the complete transfer of the sea to Russia also means some obligations for Russia. The state must protect against poachers who hunt illegally on the territory of the sea.
Bottom Features
The bottom of the sea is very diverse. There are depressions, and gutters, and many hills. The part of which ocean the Sea of Okhotsk is, also determines the nature of its shelf. According to its characteristics, it is related to the bottom of the Pacific Ocean. The Pacific Ocean is known to have the largest number of deep sea trenches on the planet. The Sea of Okhotsk is located in the transition zone between the Asian continent and the Pacific Ocean. The sea region is a huge lithospheric plate, which is located between the Eurasian, North American and Pacific plates. Pacific Ocean on the world map it is separated from the Sea of Okhotsk by the Kuril-Kamchatka deep-sea trench.
